The present invention relates to switches of the type adapted to be received over a rotatable shaft and particularly a rotatable valve shaft such that upon user rotation of the valve shaft to a desired position, the switch is actuated or deactuated for making or breaking a circuit. Such switches are employed in valves utilized for controlling flow to range top gaseous fuel burners where the valve shaft is arranged to extend through the switch and has a knob provided on the end thereof to facilitate manual actuation by the user. In gas burner valve applications, it is commonplace to have the switch close a circuit for energizing an electrical spark ignitor when the burner valve shaft has been rotated to a desired predetermined position for opening of the gas valve to permit fuel flow to the burner.
In gas burner valve switch applications, problems have been experienced with spillage of foodstuffs and liquids on the range tops and seepage of same into the interior of the switch resulting in contamination of the contacts and deterioration of the switch performance. This has been particularly troublesome where the gas burner ignitor switch is received over the shaft of the individual burner valve and secured to the valve body by fasteners such that one side of the switch is registered against the valve body and the remaining portions of the switch are exposed to the burner well in the range top. Thus, it has been desired to provide a way or means of protecting the switch in gas burner valve applications from contamination particularly from liquid foodstuffs which could result in deterioration of the electrical switch contacts within the switch housing. It has also been desired to provide a reliable gas burner valve switch that is resistant to contamination and which is economical to manufacture in high volume productions for consumer appliance applications. It has also been desired to provide a rotary switch, adapted for receipt on a shaft, which is resistant to contamination and which may be attached to continuous electrical leads.